Posthole digger



Jan. 11, 1949.; L. L. GROSSHART I I 2,458,991

' POSTHOLE DIGGER Filed April 26, 1946 2 Sheets-Sheet 1 v Patented Jan. 11,1949

UNITED STATES PATENT], OFFICE it 2,458,991

ros'rnong BIGGER. I Lloyd L. Grosshart, Boiioourt,.Kans. t ApplicationApril 26, 194 Serial No. :(ii 5,0l7

2 Claims.

. 1 V I This invention relates to an improved digging apparatus, and more particularly to an improved power transmitting system for a digging apparatus.

The invention is particularly adapted to be used in connection with a mobile power unit such as a tractor or other power plant.

' Drilling machines-of the type referred to are well known. They are driven by mobile power units in which a drill or auger is attached to the power unit and is driven thereby and moved about therewith from place to place. Such machines heretofore have been handled with manual means for elevating and lowering, or feeding, the drill or auger, resulting in much expenditure of labor and great loss of time not only in the actual boring of the holes, but in put ting the apparatus in condition for removal to another site of operation. Thus in a boring machine as heretofore in general use, it has been necessary to employ two or more men in order to accomplish the feeding or'elevating of the boring desired to use the power unit for other purposes. 3

Another object is to provide a power transmitting means for a digging (boring) apparatus car ried and operated by a mobile power unit and controlled entirely from a single point of operation for both the power unit and the digging apparatus.

The above and other objects are attained by the provision of a diggingapparatus adapted to be detachably secured to a mobile power unit, such as a tractor, and provided with a boring device having means whereby all the operations of the same can-be controlled from the drivers seat.

My invention is exemplified in the following description and illustrated in the accompanying drawings, in which:

Figure l'is a side elevation of the apparatus, partly broken away.

Fig. 2 is an end elevation of the invention.

Fig. 3 is a side view of the driving means by which the digging apparatus is driven from the mobile unit.

Fig. 4 is a view of the clutch mechanism. I Fig. 5 is a' plan view partly broken away of the stop-and-go nut mechanism.

'Fig, 6 is a section takenalong line 6-6 of Fig. 4, the threadedshaft being omitted.

Fig. 7 is a partial elevation showing the clutch mechanism in the digging or advancing position.

Fig. 8is a'partial elevation showing the clutch mechanism in the elevating or retracting position.- i

Fig. 9-is an enlarged fragmentary plan View of the clutch' braking mechanism.

Fig. 10 is a fragmentary side elevational view of' a. modified form of clutch mechanism;

.As shown in the drawings, a supporting framework 'I is provided by-which the digging apparatus as a whole is-secured in any convenient manner tov a mobile powerunit 2, such for example asa tractor. .Th diggingapparatus may take the form of a drill or. augerh3 which is .-removably secured by axnut 4 to the'lowerextremity of a thread-ed shaft .5 which extends upwardly through rotating mechanism therefor, comprising the clutch 6, bevel gear I, clutch 8, .and stop-and-go-nut 9, as will be best seen from an inspection of Figs.

, 4 and. 6..

, The bevel gear. :7 :receives its power from the bevel gear- Ill. mounted on a horizontal shaft 1 I, whichv carries at itsopposite end acog wheel 12 which is in turn-rotated by the chain l4.

As a safetvmeasure the cog wheel I2 is covcred by a cover IS.

can be seen in Fig. 3.

Shaft l! is coupled by a universal joint to a slip clutch 2i which in mm is attached to universal joint 22. The universal joint 22 is removably connected to the power take-ofiof tractor 2 in some convenient manner, such as by means of the'socket 23.

The clutch 6 is slidable up and down on the shaft 5 to whichit is keyed. The threaded shaft 5 is preferablyfprovided with a continuous keywayZLQThe'cIutch '6 has teeth 25 adapted for interengagem'ent with complementary teeth 26 on the" lower'side of the bevel gear 1, and is adapted to bemoved into and out of engagement therewithby means of the lever 21. Lever 21 is 1 pivoted'at 28.to the framework I and is retained in' either of its operative positions by a support 29.

A brake lever3ll has anotch 3| and 3N defining 2. lug 30% at.its'endforfengagement' between the teeth 25 of the clutch 6,I i norder to hold theclutch 6 against rotation" in the operative position ofthe brake. 'The brake lever-301s shown in solid lines in operative position in Fig. 9, and in dotted lines in inoperative position.

Bevel gear 1 is freely rotatable on shaft 5.

A clutch 8 is keyed upon a sleeve 32 formed on the gear "I, and is provided with teeth 33 which are engageable with complementary teeth 34 formed on the stop-and-go nut 9. The clutch 8 is operated by lever 38 pivoted at 39 on the bracket 37.

stop-and gcr nuflfl is threadediupoxi the shaft 5, and islieldiii place by a sleeve 35 with enclosed ring 36. The sleeve 35 is secured to the framework I by means of the braces 31.

A brake mechanism operated by the clutch}; is provided for the stop-and-go nut 9. Thisbrake mechanism comprises a member dll--pivoted upon the clutch 8, and extending upwardly. through a housing M on the sleeve 35to terniinateiiiah' angularly horizontally projecting portion-421 J The horizontally projecting portion 42 is adapted to engage teeth 43 on the top of. the stop-and-go nut 9, in the operativeposition of the brake mechanism. 1

The shaft 5 is steadied in the framework-l byabrace 4 4 which is securedto a bearing 45 beneath the clutch member 6.-

In utilizing the invention, the mobile unit 2' carrying, the digging apparatus is broughtto a location where it is desired to diga hole, with the boring device in elevated or retracted position.

To operate the diggingapparatus; the lever 30 ismoved so that the notch 3i is out of engagement with the teeth with the teeth 26 of gear L The clutch 8 is moved down-by, leverv 38, disengaging the teetli33 from teeth 34 ofthestopand-go nut 9, and bringing the projection 42 of the brake mechanism into engagement with-the teeth 43 of the stop-and-go nut 9, so that the latter cannot rotate; The/shaft Swill-then be turned by the gear I, and due 'to the factthat stop-,and-go nut 9 is held stationary, the shaft Bwill feed downwardly as it rotates,xcausing the drill 3 to dig the hole. I

At the completion of a boring operation' the clutch. 6, ismoved by lever 21 to. disengage teeth 25 from teeth 26, thus disconnecting clutch B from the rotating motion of gear 1; The lever is then moved to engage the notch 3| with teeth 25. The clutch 6 is then held against rotation. The clutch 8 is raised by the lever 38, engaging the teeth 33 with the teeth 34 of the stop-and-go nut 9, and raising the projection 42 of the-brake mechanism out of engagement with teeth 43 of thestop-and-go nut 9, thus permitting the-stop-and;

go; nut 9 to rotate freely.

Rotation of the gear I and the clutch 8 therewith in this condition of the apparatus will ro=- tate the stop-and-go nut 9, and due to the fact that shaft 5 is held against rotation by clutch 6, the shaftwill be raised and thus withdraw the drill 3'from the hole.

' It will of course be understood that the levers.

2l,"3fl,and38 may be extended and are'con've'r'iiently brought to same location in closeproximity to the driver's seat of the mobile power unit so that all operations of the apparatus can be controlled froinone point bya single operator.

It should bepointed out that the drill av being f easily detachable from the'shaft' 5 by the nut 4;

4 apparatus of simple design and rugged construction, adapted to bring about a substantial saving in time and labor in the digging of post holes or other boring operations.

In Figure 10 there is shown a modified form of clutch wherein the shaft 5 carries a clutch element B having teeth 6* at its lower end which are adapted to engage the tooth portion 45 of the bearing 45 which is similar to the bearing 3-5 described? above. clutch mechanism merely adds another set'df teth 6 awas at the bottom of the clutch element 6 and at the top of the bearing bracket 45, so that these teeth 6 and 45 will automatically engage when the lever zl 'is in a raised position. In this form, the lever Si? is eliminated.

What I claim is:

1; ma power transmitting system for a digging' apparatus, a source of power, a threaded shaft, mechanism operable to connect said source of power with said-shaft, said-mechanism comprising a driving gear rotatable on saidsha'ft and. having depending spaced clutch teeth; a first clutch operable to connect said gear with said shaft and. having upstanding spaced clutch teeth adapted-to fitbetween the clutchteeth-of said gear to provide connection therebetween, ,abrake lever mounted for movement toward and away from said clutch, a lug carried bysai-dbra'ke lever and adapted to be'movedinto a fitting en gagementbetween the teeth of said clutch-for: holdingsaid clutch againstrotation, a stop-andg0: t threaded-on Said shaft; a second clutch operable to connect said gear with said stop-and gonna-brake means operable to prevent rotation ofsaid-stop-and-go nut, and means for bringing said last mentioned-"brake means into operating. position with said stop-and-go nut upon release of said second clutch.

2-. Ina power transmitting system for adigging. apparatus, a source of power, a threadedshaft, mechanism operable to connect' said source of power With-said shaft, said mechanism comprising-adriving gear rotatableon said shaft and having-protrudingteeth, a guide for said nut', a

'brake mechanism comprising amemberslidably extending through said guide andsecuredat one end-to said second clutch, said member of saidbrake mechanism havingan angular portion nor-' mally overhanging the teeth of said stop-and-go nut, ,and-means'for simultaneously moving said second clutch out of engagement withsaid-stopand-go nut-and moving the angular portion of the-brake mechanism into an interfitting position between the teeth of the stop-and-go nut to hold said nut against rotation.

LLOYD L. GROSSHART-fi REFERENCES CITED The following references are of record inthe file of this patent:

UNITED STATES PATENTS Number Name Date 1,376,045 Skottet a1. Apr.26, 1921 2,273,203 Keene et a1. .Feb;17,'1942' 2,416,036 Zimmerlein et'al; Feb. 18, 1947 

